/*
 * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

package sun.jvm.hotspot.runtime;

import java.util.*;

public class ThreadStackTrace {
    private JavaThread                        thread;
    private int                               depth;  // number of stack frames added
    private ArrayList<StackFrameInfo>         frames;

    public ThreadStackTrace(JavaThread t) {
        this.thread = t;
        this.depth = 0;
        this.frames = new ArrayList<StackFrameInfo>();
    }

    public int getStackDepth() {
        return depth;
    }

    public StackFrameInfo stackFrameAt(int index) {
        return frames.get(index);
    }

    public void dumpStack(int maxDepth) {
        if (!thread.isJavaThread()) {
            System.out.println("dumpStack: not java Thread.");
            return;
        }
        try {
            for (JavaVFrame vf = thread.getLastJavaVFrameDbg(); vf != null; vf = vf.javaSender()) {
                StackFrameInfo frame = new StackFrameInfo(vf);
                frames.add(frame);
                depth++;

                if (maxDepth > 0 && depth == maxDepth) {
                    // Skip frames if more than maxDepth
                    break;
                }
            }
        } catch (Exception e) {
            System.out.println("Error occurred during stack walking:");
            e.printStackTrace();
        }
    }
}